RESONANCE RAMAN-SPECTRA OF THE NITRIC-OXIDE ADDUCTS OF FERROUS CYTOCHROME P450CAM IN THE PRESENCE OF VARIOUS SUBSTRATES
RESONANCE RAMAN-SPECTRA OF THE NITRIC-OXIDE ADDUCTS OF FERROUS CYTOCHROME P450CAM IN THE PRESENCE OF VARIOUS SUBSTRATES
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DOI：
10.1021/ja00026a008
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发表时间：
1991-12-18
影响因子：
15
通讯作者：
KINCAID, JR
中科院分区：
文献类型：
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作者：
HU, SZ;KINCAID, JR
报道了金刚烷酮、樟脑和去甲樟脑结合形式以及无底物形式的亚铁细胞色素 P450cam（来自恶臭假单胞菌）的一氧化氮加合物的共振拉曼光谱。 nu-4 (1372 cm-1) 和 nu-3 (1499 cm-1) 模式的频率降低与内源硫醇盐连接的存在一致。亚铁细胞色素 P450cam 自然丰度一氧化氮加合物的三种预期正态模式在 1591、554 和 446 cm-1 处检测到，并根据正态模式分析分别分配给 nu(N-O)、nu(Fe(II)-NO) 和 delta(Fe(II)-NO)，尽管表明了后两种模式的广泛混合。随着 NO 质量逐渐增加一个原子单位，554 cm-1 处的强谱带移动到 539 ((NO)-N-15-O-16)、552 ((NO)-N-14-O-18) 和 538 cm-1 ((NO)-N-15-O-18)，而 446-cm-1 特征表现出单调下移到 442 ((NO)-N-15-O-16) 和 440 ((NO)-N-14-O-18 和 437 cm-1 ((NO)-N-15-O-18)。这两个谱带的底物敏感性与本质上线性 Fe(II)-CO 观察到的底物敏感性明显不同 (Uno, T., et al. J. Biol. Chem. 1985, 260, 2023-2026）和 Fe(III)-NO（Hu, S.；Kincaid, J. J. Am. Chem. Soc. 1991, 113, 2843-2850）加合物，讨论了与酶催化的樟脑区域和立体特异性羟基化的关系。
Resonance Raman spectra of the nitric oxide adducts of ferrous cytochrome P450cam (from Pseudomonas putida) in the adamantanone-, camphor-, and norcamphor-bound forms, as well as in the substrate-free form, are reported. The lowered frequency of the nu-4 (1372 cm-1) and nu-3 (1499 cm-1) modes is consistent with the presence of endogenous thiolate ligation. The three expected normal modes of the natural abundance nitric oxide adduct of ferrous cytochrome P450cam are detected at 1591, 554, and 446 cm-1 and are assigned to nu(N-O), nu(Fe(II)-NO), and delta(Fe(II)-NO), respectively, based on a normal mode analysis, although extensive mixing of the latter two modes is indicated. The very strong band at 554 cm-1 shifts to 539 ((NO)-N-15-O-16), 552 ((NO)-N-14-O-18), and 538 cm-1 ((NO)-N-15-O-18) as the mass of NO increases incrementally by one atomic unit, while the 446-cm-1 feature exhibits a monotonous downshift to 442 ((NO)-N-15-O-16), and 440 ((NO)-N-14-O-18, and 437 cm-1 ((NO)-N-15-O-18). The substrate sensitivity of these two bands, distinctly different from those observed for the intrinsically linear Fe(II)-CO (Uno, T., et al. J. Biol. Chem. 1985, 260, 2023-2026) and Fe(III)-NO (Hu, S.; Kincaid, J. J. Am. Chem. Soc. 1991, 113, 2843-2850) adducts, is discussed in relation to the enzyme-catalyzed regio- and stereospecific hydroxylation of camphor.